diff --git a/codes/cpp/chapter_tree/avl_tree.cpp b/codes/cpp/chapter_tree/avl_tree.cpp
deleted file mode 100644
index 8bc0741d..00000000
--- a/codes/cpp/chapter_tree/avl_tree.cpp
+++ /dev/null
@@ -1,228 +0,0 @@
-/**
- * File: avl_tree.cpp
- * Created Time: 2022-12-2
- * Author: mgisr (maguagua0706@gmail.com)
- */
-
-#include "../include/include.hpp"
-
-class AvlTree {
-private:
-    TreeNode *root{};
-    static bool isBalance(const TreeNode *p);
-    static int getBalanceFactor(const TreeNode *p);
-    static void updateHeight(TreeNode *p);
-    void fixBalance(TreeNode *p);
-    static bool isLeftChild(const TreeNode *p);
-    static TreeNode *&fromParentTo(TreeNode *node);
-public:
-    AvlTree() = default;
-    AvlTree(const AvlTree &p) = default;
-    const TreeNode *search(int val);
-    bool insert(int val);
-    bool remove(int val);
-    void printTree();
-};
-
-// 判断该结点是否平衡
-bool AvlTree::isBalance(const TreeNode *p) {
-    int balance_factor = getBalanceFactor(p);
-    if (-1 <= balance_factor && balance_factor <= 1) { return true; }
-    else { return false; }
-}
-
-// 获取当前结点的平衡因子
-int AvlTree::getBalanceFactor(const TreeNode *p) {
-    if (p->left == nullptr && p->right == nullptr) { return 0; }
-    else if (p->left == nullptr) { return (-1 - p->right->height); }
-    else if (p->right == nullptr) { return p->left->height + 1; }
-    else { return p->left->height - p->right->height; }
-}
-
-// 更新结点高度
-void AvlTree::updateHeight(TreeNode *p) {
-    if (p->left == nullptr && p->right == nullptr) { p->height = 0; }
-    else if (p->left == nullptr) { p->height = p->right->height + 1; }
-    else if (p->right == nullptr) { p->height = p->left->height + 1; }
-    else { p->height = std::max(p->left->height, p->right->height) + 1; }
-}
-
-void AvlTree::fixBalance(TreeNode *p) {
-    // 左旋操作
-    auto rotate_left = [&](TreeNode *node) -> TreeNode * {
-        TreeNode *temp = node->right;
-        temp->parent = p->parent;
-        node->right = temp->left;
-        if (temp->left != nullptr) {
-            temp->left->parent = node;
-        }
-        temp->left = node;
-        node->parent = temp;
-        updateHeight(node);
-        updateHeight(temp);
-        return temp;
-    };
-    // 右旋操作
-    auto rotate_right = [&](TreeNode *node) -> TreeNode * {
-        TreeNode *temp = node->left;
-        temp->parent = p->parent;
-        node->left = temp->right;
-        if (temp->right != nullptr) {
-            temp->right->parent = node;
-        }
-        temp->right = node;
-        node->parent = temp;
-        updateHeight(node);
-        updateHeight(temp);
-        return temp;
-    };
-    // 根据规则选取旋转方式
-    if (getBalanceFactor(p) > 1) {
-        if (getBalanceFactor(p->left) > 0) {
-            if (p->parent == nullptr) { root = rotate_right(p); }
-            else { fromParentTo(p) = rotate_right(p); }
-        } else {
-            p->left = rotate_left(p->left);
-            if (p->parent == nullptr) { root = rotate_right(p); }
-            else { fromParentTo(p) = rotate_right(p); }
-        }
-    } else {
-        if (getBalanceFactor(p->right) < 0) {
-            if (p->parent == nullptr) { root = rotate_left(p); }
-            else { fromParentTo(p) = rotate_left(p); }
-        } else {
-            p->right = rotate_right(p->right);
-            if (p->parent == nullptr) { root = rotate_left(p); }
-            else { fromParentTo(p) = rotate_left(p); }
-        }
-    }
-}
-
-// 判断当前结点是否为其父节点的左孩子
-bool AvlTree::isLeftChild(const TreeNode *p) {
-    if (p->parent == nullptr) { return false; }
-    return (p->parent->left == p);
-}
-
-// 返回父节点指向当前结点指针的引用
-TreeNode *&AvlTree::fromParentTo(TreeNode *node) {
-    if (isLeftChild(node)) { return node->parent->left; }
-    else { return node->parent->right; }
-}
-
-const TreeNode *AvlTree::search(int val) {
-    TreeNode *p = root;
-    while (p != nullptr) {
-        if (p->val == val) { return p; }
-        else if (p->val > val) { p = p->left; }
-        else { p = p->right; }
-    }
-    return nullptr;
-}
-
-bool AvlTree::insert(int val) {
-    TreeNode *p = root;
-    if (p == nullptr) {
-        root = new TreeNode(val);
-        return true;
-    }
-    for (;;) {
-        if (p->val == val) { return false; }
-        else if (p->val > val) {
-            if (p->left == nullptr) {
-                p->left = new TreeNode(val, p);
-                break;
-            } else {
-                p = p->left;
-            }
-        } else {
-            if (p->right == nullptr) {
-                p->right = new TreeNode(val, p);
-                break;
-            } else {
-                p = p->right;
-            }
-        }
-    }
-    for (; p != nullptr; p = p->parent) {
-        if (!isBalance(p)) {
-            fixBalance(p);
-            break;
-        } else { updateHeight(p); }
-    }
-    return true;
-}
-
-bool AvlTree::remove(int val) {
-    TreeNode *p = root;
-    if (p == nullptr) { return false; }
-    while (p != nullptr) {
-        if (p->val == val) {
-            TreeNode *real_delete_node = p;
-            TreeNode *next_node;
-            if (p->left == nullptr) {
-                next_node = p->right;
-                if (p->parent == nullptr) { root = next_node; }
-                else { fromParentTo(p) = next_node; }
-            } else if (p->right == nullptr) {
-                next_node = p->left;
-                if (p->parent == nullptr) { root = next_node; }
-                else { fromParentTo(p) = next_node; }
-            } else {
-                while (real_delete_node->left != nullptr) {
-                    real_delete_node = real_delete_node->left;
-                }
-                std::swap(p->val, real_delete_node->val);
-                next_node = real_delete_node->right;
-                if (real_delete_node->parent == p) { p->right = next_node; }
-                else { real_delete_node->parent->left = next_node; }
-            }
-            if (next_node != nullptr) {
-                next_node->parent = real_delete_node->parent;
-            }
-            for (p = real_delete_node; p != nullptr; p = p->parent) {
-                if (!isBalance(p)) { fixBalance(p); }
-                updateHeight(p);
-            }
-            delete real_delete_node;
-            return true;
-        } else if (p->val > val) {
-            p = p->left;
-        } else {
-            p = p->right;
-        }
-    }
-    return false;
-}
-
-void inOrder(const TreeNode *root) {
-    if (root == nullptr) return;
-    inOrder(root->left);
-    cout << root->val << ' ';
-    inOrder(root->right);
-}
-
-void AvlTree::printTree() {
-    inOrder(root);
-    cout << endl;
-}
-
-int main() {
-    AvlTree tree = AvlTree();
-    // tree.insert(13);
-    // tree.insert(24);
-    // tree.insert(37);
-    // tree.insert(90);
-    // tree.insert(53);
-
-    tree.insert(53);
-    tree.insert(90);
-    tree.insert(37);
-    tree.insert(24);
-    tree.insert(13);
-    tree.remove(90);
-    tree.printTree();
-    const TreeNode *p = tree.search(37);
-    cout << p->val;
-    return 0;
-}
\ No newline at end of file